As the above reply becomes a means for discussion and sharing information among the internet users, the ‘reply culture’ is a new cultural trend. In particular, the reply has a bilateral nature in that one can post his own opinion to a post and then another user can post different opinion to the original post or to other user's opinion previously posted; because of this attribute of reply, the reply is widely used in sharing information and exchanging opinions on specific issues. In addition, once users write diverse opinions with reply after reading news articles or posts, the opinions can be another source of information in addition to the original article or post. For example, one can comprehend the content and users' assessment of the original article or post without reading the original text; and the concern of users on the article can be grasped by the number of replies regardless of the content of replies.
While the reply culture was originally started and developed with text post, it is also applied to video contents as the web sites, which provide watching video contents online such as movie, music video, and internet lecture using communications networks, are extensively used and users watch various video contents anytime anywhere.
However, when users watching the same video contents want to have a conversation or exchange opinions one another, compared with text that can be read by users at once, the use of reply culture in video contents has a problem that the effect of the above reply function is depreciated because users require watching the video content while playing it to the end. For example, if a reply regarding a video content is posted, other users can hardly know the part of the video content referred by the reply; even if a reply comments a specific part of the video, the specific part can be confirmed by playing the corresponding video content one after another because the video content is not divided as sections. Considering the problems described above, technologies that allow posting a reply at a specified time are being developed.
Hereinafter, the prior art that allow posting a reply at a specified time and related problems are described as follows.
1. Korea disclosed patent No. 2010-0100405 (Sep. 15, 2010): it enables a user to write a reply directly on the playback screen while playing a video and other user can see the inserted reply and write additional reply. But this method provides watching different replies of other users at each time of playback like subtitles and thus it is far from identifying the video based on the content of reply or number of replies.
2. Korea disclosed patent No. 2012-0101212 (Sep. 13, 2012): users write reply at a specific point of time during the playback of a video and the record for replies is provided; if a user selects a specific reply, the video on the timeline of writing the reply is played. However, it is only for playing the video at the time of writing the reply and if a user want to identify the content of the video it is required to play the video.
In addition, as the web sites providing video service increases, competition among the web sites becomes more intensified; considering the circumstances, the web sites providing video service are required to develop new additional services other than the basic service providing videos only in order to get users' interest actively.